As machines are commonly cheaper to replace people, industrial robots are usually used to produce productions in industrial manufacturing and other related technical fields. Most multi joint industrial robots in the current market are ordinary 6-DOF (six-joint) robots. However, with increasingly higher requirements on the production efficiency in industry, it is urgently necessary to increase the operation speed of the robot without increasing the energy consumption, so as to maximize the economic benefits.
Based on this background, it needs to invent a new robot for meeting the requirement of small operation space. The application environment requires such robot which has lower occupation area and quick movement speed and the transportation of the target between the front and rear position does not occupy additional avoidance space. However, the traditional 6-DOF robot is useless in such condition. The bi-spin robot breaks the structure form of the traditional general robot, and provides a 6-DOF robot with a creative structure, so that the robot can not only own the functions of generally 6-DOF robot which only has external rotation function but also realize the internal rotation. In detail, the function called “external rotation” means that when the robot executes external rotation, the upper arm usually rotates about one axis and the trajectory of the end effector is an arc. However, the function called “internal rotation” means that when the robot executes internal rotation, the lower arm will cut across the interior space close to the upper arm instead of occupying external space. Therefore it is called a bi-spin robot. This kind of robot can greatly reduce the space required for installing and the inertia in the operation process, and results in greatly increased operation speed and reduced operation time.
Moreover, there are a lot of 6-DOF robots in the current market. The former three joints of various 6-DOF robots are similar, while the last three joints of various 6-DOF robots mainly have two different kinds of structure, wherein the first type has a postpositional joint, which is represented by KUKA, the second type has a prepositional joint, which is represented by FUNAC, Yaskawa, etc., and all the motors are horizontally installed. The volume of the arm of the second type of robot depends on the length of the motor, so that the weight of most manipulators is very heavy, which causes larger weight of the robot.
In addition, the 6-DOF robot is frequently used in the industry. As to the existing 6-DOF robot, the fifth motor is directly connected to a wrist. Since the weight of the fifth motor is large, the rotational inertia can be very large and consume a lot of energy, which is harmful to energy conservation and environment protection. Moreover, the existing wrist movement inertia is also very large, and all these factors can lead to inflexible movement and large energy consumption for the robot.